1. Field of the Invention
The present invention relates to a method and an apparatus for estimating properties of a cylindrical object; in particular, to a method and an apparatus for measuring the abrasion and friction coefficient between flexible materials, such as magnetic recording tape, paper, thread, etc., and said cylindrical object.
As the need for the use of materials in harsh conditions increases, improvement of the abrasion resistance and lubrication properties of the materials is required. Thus, in measuring the reliability of materials, the testing of materials' abrasion and friction coefficients is very important. Further, where a coating is applied to materials to improve abrasion resistance and lubrication, it is imperative to evaluate the properties and reliability of the coating layer. From such testing results, the development of the coating layer, improvement of the properties, and development and improvement of synthetic processes may be achieved.
2. Description of the Prior Art
To evaluate the abrasion resistance of materials, various methods exist, such as ball-on-disk testing, pin-on-disk testing, scratch testing, etc. However, the above methods can only be applied to materials with flat surfaces. Further, the materials to be used in the testing, (i.e., ball, pin, and indentor) are severely limited as to their composition and shape. One example of this is shown in FIG. 1, which is a schematic view of a testing apparatus using the pin-on-disk testing method. [Testing of Metallic and Inorganic Coatings (Ed. W. B. Harding and G. A. DiBari) pp. 310, STP 947, ASTM, Philadelphia, Pa. (1987)] In FIG. 1, reference numeral 11 denotes the pressure rod which is the relative testing material and reference numeral 12 denotes the rotational disk test specimen. As seen in FIG. 1, rotational disk testing object 12 must have a flat surface configuration. The information which may be obtained through such testing is limited to the friction coefficient and abrasion resistance between the testing object and the relative testing material in the shape of a ball or pin. Further, although abrasion property testing methods such as the pin on cylinder method, rectangular flats on rotating cylinder method, four-ball method, crossed-cylinder method, disk-on-disk method, etc., have been proposed for testing objects with cylindrical or ball shapes, the shape of the relative testing materials is still limited.